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Make send/receive-pack be closer to doing something interesting

maint
Linus Torvalds 20 years ago
parent
commit
f3a3214e83
  1. 7
      Makefile
  2. 117
      pkt-line.c
  3. 12
      pkt-line.h
  4. 126
      receive-pack.c
  5. 12
      send-pack.c

7
Makefile

@ -9,7 +9,7 @@ @@ -9,7 +9,7 @@
# BREAK YOUR LOCAL DIFFS! show-diff and anything using it will likely randomly
# break unless your underlying filesystem supports those sub-second times
# (my ext3 doesn't).
COPTS=-O2
COPTS=
CFLAGS=-g $(COPTS) -Wall

prefix=$(HOME)
@ -46,9 +46,10 @@ install: $(PROG) $(SCRIPTS) @@ -46,9 +46,10 @@ install: $(PROG) $(SCRIPTS)

LIB_OBJS=read-cache.o sha1_file.o usage.o object.o commit.o tree.o blob.o \
tag.o date.o index.o diff-delta.o patch-delta.o entry.o \
epoch.o refs.o csum-file.o verify_pack.o
epoch.o refs.o csum-file.o verify_pack.o pkt-line.o
LIB_FILE=libgit.a
LIB_H=cache.h object.h blob.h tree.h commit.h tag.h delta.h epoch.h csum-file.h pack.h
LIB_H=cache.h object.h blob.h tree.h commit.h tag.h delta.h epoch.h csum-file.h \
pack.h pkt-line.h

LIB_H += strbuf.h
LIB_OBJS += strbuf.o

117
pkt-line.c

@ -0,0 +1,117 @@ @@ -0,0 +1,117 @@
#include "cache.h"
#include "pkt-line.h"

/*
* Write a packetized stream, where each line is preceded by
* its length (including the header) as a 4-byte hex number.
* A length of 'zero' means end of stream (and a length of 1-3
* would be an error).
*
* This is all pretty stupid, but we use this packetized line
* format to make a streaming format possible without ever
* over-running the read buffers. That way we'll never read
* into what might be the pack data (which should go to another
* process entirely).
*
* The writing side could use stdio, but since the reading
* side can't, we stay with pure read/write interfaces.
*/
static void safe_write(int fd, const void *buf, unsigned n)
{
while (n) {
int ret = write(fd, buf, n);
if (ret > 0) {
buf += ret;
n -= ret;
continue;
}
if (!ret)
die("write error (disk full?)");
if (errno == EAGAIN || errno == EINTR)
continue;
die("write error (%s)", strerror(errno));
}
}

/*
* If we buffered things up above (we don't, but we should),
* we'd flush it here
*/
void packet_flush(int fd)
{
safe_write(fd, "0000", 4);
}

#define hex(a) (hexchar[(a) & 15])
void packet_write(int fd, const char *fmt, ...)
{
static char buffer[1000];
static char hexchar[] = "0123456789abcdef";
va_list args;
unsigned n;

va_start(args, fmt);
n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args);
va_end(args);
if (n >= sizeof(buffer)-4)
die("protocol error: impossibly long line");
n += 4;
buffer[0] = hex(n >> 12);
buffer[1] = hex(n >> 8);
buffer[2] = hex(n >> 4);
buffer[3] = hex(n);
safe_write(fd, buffer, n);
}

static void safe_read(int fd, void *buffer, unsigned size)
{
int n = 0;

while (n < size) {
int ret = read(fd, buffer + n, size - n);
if (ret < 0) {
if (errno == EINTR || errno == EAGAIN)
continue;
die("read error (%s)", strerror(errno));
}
if (!ret)
die("unexpected EOF");
n += ret;
}
}

int packet_read_line(int fd, char *buffer, unsigned size)
{
int n;
unsigned len;
char linelen[4];

safe_read(fd, linelen, 4);

len = 0;
for (n = 0; n < 4; n++) {
unsigned char c = linelen[n];
len <<= 4;
if (c >= '0' && c <= '9') {
len += c - '0';
continue;
}
if (c >= 'a' && c <= 'f') {
len += c - 'a' + 10;
continue;
}
if (c >= 'A' && c <= 'F') {
len += c - 'A' + 10;
continue;
}
die("protocol error: bad line length character");
}
if (!len)
return 0;
len -= 4;
if (len >= size)
die("protocol error: bad line length %d", len);
safe_read(fd, buffer, len);
buffer[len] = 0;
return len;
}

12
pkt-line.h

@ -0,0 +1,12 @@ @@ -0,0 +1,12 @@
#ifndef PKTLINE_H
#define PKTLINE_H

/*
* Silly packetized line writing interface
*/
void packet_flush(int fd);
void packet_write(int fd, const char *fmt, ...);

int packet_read_line(int fd, char *buffer, unsigned size);

#endif

126
receive-pack.c

@ -1,4 +1,5 @@ @@ -1,4 +1,5 @@
#include "cache.h"
#include "pkt-line.h"
#include <sys/wait.h>

static const char receive_pack_usage[] = "git-receive-pack [--unpack=executable] <git-dir> [heads]";
@ -26,61 +27,9 @@ static int path_match(const char *path, int nr, char **match) @@ -26,61 +27,9 @@ static int path_match(const char *path, int nr, char **match)
return 0;
}

static void safe_write(int fd, const void *buf, unsigned n)
{
while (n) {
int ret = write(fd, buf, n);
if (ret > 0) {
buf += ret;
n -= ret;
continue;
}
if (!ret)
die("write error (disk full?)");
if (errno == EAGAIN || errno == EINTR)
continue;
die("write error (%s)", strerror(errno));
}
}

/*
* If we buffered things up above (we don't, but we should),
* we'd flush it here
*/
static void flush_safe(int fd)
{
}

/*
* Write a packetized stream, where each line is preceded by
* its length (including the header) as a 4-byte hex number.
* A length of 'zero' means end of stream (and a length of 1-3
* would be an error).
*/
#define hex(a) (hexchar[(a) & 15])
static void packet_write(const char *fmt, ...)
{
static char buffer[1000];
static char hexchar[] = "0123456789abcdef";
va_list args;
unsigned n;

va_start(args, fmt);
n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args);
va_end(args);
if (n >= sizeof(buffer)-4)
die("protocol error: impossibly long line");
n += 4;
buffer[0] = hex(n >> 12);
buffer[1] = hex(n >> 8);
buffer[2] = hex(n >> 4);
buffer[3] = hex(n);
safe_write(1, buffer, n);
}

static void show_ref(const char *path, unsigned char *sha1)
{
packet_write("%s %s\n", sha1_to_hex(sha1), path);
packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
}

static int read_ref(const char *path, unsigned char *sha1)
@ -137,66 +86,6 @@ static void write_head_info(const char *base, int nr, char **match) @@ -137,66 +86,6 @@ static void write_head_info(const char *base, int nr, char **match)
}
}

/*
* This is all pretty stupid, but we use this packetized line
* format to make a streaming format possible without ever
* over-running the read buffers. That way we'll never read
* into what might be the pack data (which should go to another
* process entirely).
*
* The writing side could use stdio, but since the reading
* side can't, we stay with pure read/write interfaces.
*/
static void safe_read(int fd, void *buffer, unsigned size)
{
int n = 0;

while (n < size) {
int ret = read(0, buffer + n, size - n);
if (ret < 0) {
if (errno == EINTR || errno == EAGAIN)
continue;
die("read error (%s)", strerror(errno));
}
if (!ret)
die("unexpected EOF");
n += ret;
}
}

static int safe_read_line(char *buffer, unsigned size)
{
int n, len;

safe_read(0, buffer, 4);

len = 0;
for (n = 0; n < 4; n++) {
unsigned char c = buffer[n];
len <<= 4;
if (c >= '0' && c <= '9') {
len += c - '0';
continue;
}
if (c >= 'a' && c <= 'f') {
len += c - 'a' + 10;
continue;
}
if (c >= 'A' && c <= 'F') {
len += c - 'A' + 10;
continue;
}
die("protocol error: bad line length character");
}
if (!len)
return 0;
if (len < 4 || len >= size)
die("protocol error: bad line length %d", len);
safe_read(0, buffer + 4, len - 4);
buffer[len] = 0;
return len;
}

struct line {
struct line *next;
char data[0];
@ -213,7 +102,7 @@ static void execute_commands(void) @@ -213,7 +102,7 @@ static void execute_commands(void)
struct line *line = commands;

while (line) {
printf("%s", line->data);
fprintf(stderr, "%s", line->data);
line = line->next;
}
}
@ -223,7 +112,7 @@ static void read_head_info(void) @@ -223,7 +112,7 @@ static void read_head_info(void)
struct line **p = &commands;
for (;;) {
static char line[1000];
int len = safe_read_line(line, sizeof(line));
int len = packet_read_line(0, line, sizeof(line));
struct line *n;
if (!len)
break;
@ -242,8 +131,8 @@ static void unpack(void) @@ -242,8 +131,8 @@ static void unpack(void)
if (pid < 0)
die("unpack fork failed");
if (!pid) {
char *const envp[] = { "GIT_DIR=.", NULL };
execle(unpacker, unpacker, NULL, envp);
setenv("GIT_DIR", ".", 1);
execlp(unpacker, unpacker, NULL);
die("unpack execute failed");
}

@ -311,8 +200,7 @@ int main(int argc, char **argv) @@ -311,8 +200,7 @@ int main(int argc, char **argv)
write_head_info("refs/", nr_heads, heads);

/* EOF */
safe_write(1, "0000", 4);
flush_safe(1);
packet_flush(1);

read_head_info();
unpack();

12
send-pack.c

@ -1,4 +1,5 @@ @@ -1,4 +1,5 @@
#include "cache.h"
#include "pkt-line.h"

static const char send_pack_usage[] = "git-send-pack [--exec=other] destination [heads]*";

@ -8,13 +9,16 @@ static int send_pack(int in, int out) @@ -8,13 +9,16 @@ static int send_pack(int in, int out)
{
for (;;) {
static char buffer[1000];
int ret = read(in, buffer, sizeof(buffer));
if (ret > 0) {
write(1, buffer, ret);
int len;

len = packet_read_line(in, buffer, sizeof(buffer));
if (len > 0) {
write(2, buffer, len);
continue;
}
break;
}
packet_flush(out);
close(out);
return 0;
}
@ -77,7 +81,7 @@ static int setup_connection(int fd[2], char *url, char **heads) @@ -77,7 +81,7 @@ static int setup_connection(int fd[2], char *url, char **heads)
if (host)
execlp("ssh", "ssh", host, command, NULL);
else
execlp(host, command, NULL);
execlp("sh", "sh", "-c", command, NULL);
die("exec failed");
}
fd[0] = pipefd[0][0];

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